Hello Guys,
I need to model the curve in the picture so it has a thickness of 2mm, like it was a bended piece of metal . I know how to build it out of separate shapes and then combine them. But is there a way to do it all in one?

Hi dune1982, well the wireframe there is ambiguous, there are 2 ways you could have a bent shape from that, either like this:

Or like this:

In either case, I'd recommend leaving the corners at the ends to be sharp initially, then build the base shape with Extrude, then thicken the extruded joined surface object into a solid using Construct > Offset > Shell (or you can Offset the curve and have the thickened shape right from the initial Extrude), then doing the rounded corners at the ends by selecting the end edges and using Construct > Fillet:

Right now you've made things more difficult by trying to incorporate all the final rounded edges in your wireframe from the start, it's easier to generate some of those rounded edges by using filleting rather than having them in your initial curves. Often times with NURBS modeling it's good for some portions of your final model to be built by cutting away material by booleans or in this case fillets, rather than trying to draw every single curve in the final model right from the start. The curves you want to draw are the ones that will make an initial simplified extended piece of base material.

Hi dune1982, you're welcome! It is actually possible to do this with one single command, having the curves configured like this, with these 2 lines as the profile curves and the other curves joined up as rails:

With that configuration it's also possible to use Network or also Loft between the top and bottom ones to do it in one command.

However, all of these "do it in one command" options will generate a lower quality result because it's not good to have a surface corner that has tangent edges in it as you will get here, the natural definition of the surface normal at such areas becomes poorly defined. It's better for a rounded corner of a surface to be done by having a square cornered surface that has trim curves on it instead of that.

Usually when there's almost any kind of irregularity to a boundary (like edges tangent, having a complex edge with zig-zags or whatever), it's usually best to have an extended simple base surface that is then trimmed to the boundary rather than trying to generate the initial surface directly to that boundary.

@Pilou - yes that's another possibility, it's just more convenient to use a method that uses fewer curves to do the job.